"I think we all wanted Avastin to succeed but the reality is that these studies did not bear out that hope," said Natalie Compagni-Portis, a patient representative on the six-member panel.

The vote is not binding. FDA Commissioner Margaret Hamburg makes the final decision after July 28.

The FDA began steps to remove Avastin's breast cancer approval in December, but its drugmaker, Roche, took the rare step of appealing that decision and lobbied the agency and Congress for a second hearing. The contentious tone of the two-day hearing underscored the difficulty of removing an option for cancer patients, even when backed by scientific evidence.

"What do you want us to take!? We have nothing else!" shouted Christi Turnage, of Madison, Miss after the vote concluded. Turnage said her cancer has been undetectable for more than two years since taking Avastin.

Avastin is FDA-approved for colon, lung, kidney and brain cancer, which were not part of the debate. Doctors will still be allowed to prescribe Avastin for breast cancer, though insurers may not foot the bill - a year of treatment can cost $100,000.

Roche argued the drug should remain available while it conducts more research on which patients benefit from the injectable drug. The drug is approved for breast cancer that has spread to other parts of the body - cancer generally considered incurable.

"The data tell us it is better for women diagnosed with metastatic breast cancer to have Avastin as an approved treatment option," said Hal Barron, Roche executive vice president.

But the panelists shot that notion down, saying Avastin's ability to slow breast cancer tumor growth - measured by imaging scans - has not translated into meaningful benefit for patients.

"As treating clinicians we have to ask ourselves: What are we doing in terms of helping patients?" said panelist Dr. Wyndam Wilson of the National Cancer Institute. "Simply delaying a change in a CT scan for a month or two is not significant unless it's accompanied by other improvements."

The FDA granted Avastin accelerated approval in 2008 based on one study in which it slowed breast cancer tumor growth for more than five months when combined with chemotherapy. But in follow-up studies the delay shrunk to less than three months. Across all studies, patients taking Avastin did not live any longer and suffered side effects like infection, high blood pressure and blood clots.

"No trial has shown that patients treated with Avastin lived longer than those not treated with Avastin," said FDA's director for new drugs, Dr. John Jenkins. "All clinical trials show an increase in serious adverse events."

Most cancer experts say the drug should remain available for patients who are already responding well, despite the pending withdrawal.

"I think the FDA is doing the right thing since the drug has some serious complications," said Dr. Stephanie Bernik of Lenox Hill Hospital in New York. "However, there are definitely patients who are benefiting from the drug and if the FDA completely withdraws approval those patients may find it hard to get access."